this presidential campaign has been going on for nearly two years and finally it's debate season for the nominees. the time when americans seem to really start paying attention. president obama's rehearsing with senator john kerry and mitt romney is squaring off against senator rob portman. both candidates have challenges and checklists. president obama's working on shorter answers, trying to avoid sounding like the professor he was before the white house. democrats say he needs to look strong and forceful and not appear irritated or impatient. >> they're trying to get him into the mode of being able to answer questions, short, concisely, and to the point, and so it's much more like his mannerisms and his style and the way he comes across as opposed to information in this. >> reporter: and mitt romney? he has to seem relatable, especially after his 47% comment. how can he do that? show compassion? show he's competent and connect with the voters? >> on those three cs that's where he really has got to do well. >> reporter: romney arrived in colorado to continue his debate prep but took